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Wind energy in the UK could increase by 10% if the world warms to 1.5C above pre-industrial temperatures, a new study finds.

The research is the first to look at this question using new climate model experiments specifically run to assess the small changes between current global temperatures and 1.5C of warming.

The largest changes are found for summer months in the UK, the lead author tells Carbon Brief. At these times, wind energy typically contributes less to the UK energy mix. Any increase could help to offset increased air conditioning use as temperatures rise, he adds.

However, the results appear to contradict a previous study, which found wind potential would fall with rising temperatures.

1.5C changes

The 2015 Paris Agreement called on countries to pursue efforts to limit global temperature rise to 1.5C. It also asked the International Panel on Climate Change (IPCC) to prepare a special report on 1.5C, which will be released later this year. As a result, many climate scientists are currently assessing the impacts of 1.5C.

As part of this work, researchers have developed a new climate modelling effort known as HAPPI (Half a degree Additional warming, Prognosis and Projected Impacts). This assesses the impacts of reaching 1.5C warming – around “half a degree” above current temperatures – which other models may not be sensitive enough to detect.

The study, published today in Environmental Research Letters, uses HAPPI models to look at how European onshore wind energy potential would change if global temperatures rise by 1.5C. (The study does not examine offshore wind energy potential.)

Projected changes in wind energy potential are shown in the panels below, for four different HAPPI global climate models. Each model makes slightly different assumptions about uncertain atmospheric patterns and processes.

Change in median annual zonal wind speed at 850 hectopascals (hPa) pressure between the historical and 1.5C experiments, in each of four HAPPI global climate models used in the study. Source: Hosking et al (2018).

As the panels show, the models agree that wind energy potential will generally increase in northern Europe and decrease in southern Europe. All four models simulate that the North Atlantic westerly winds will shift northwards, the paper says.

This suggests wind power could become more viable in areas of Germany, Poland and Lithuania, as well as the UK, the paper says. The paper adds that modelled reductions in southern European wind resource are likely to be “negligible”.

The study shows wind generation in the UK could increase by up to around 10%, says Dr Scott Hosking, a climate scientist at the British Antarctic Survey and lead author of the paper. He tells Carbon Brief:

“We’re not talking about changing technology, we just say if you take the current windfarms and the current technology, and you added onto that the change in wind that we’d see in a 1.5C world, [this is the] increase in energy coming from those turbines.”

Summer winds

The researchers also looked for changes in wind’s seasonal variability. To do this, they combined the results of the four models HAPPI together, only taking a result where at least three of the four HAPPI models agreed on the sign of the change (increase or decrease in wind potential).

Glossary

Load factor: A measure of the average output of a power station, relative to its installed capacity. This depends on technical and economic factors. For individual gas, coal or nuclear plants the load factor can in theory be above 90%. However, UK fleet-wide averages are much lower. The range of fleet-wide average load factors during 2010-2014 was 28-62% for gas, 40-57% for coal and 65-74% for nuclear. The range of rates for the UK’s renewable fleets was 10-11% for solar, 22-28% for onshore and 30-38% for offshore wind. Newer windfarms tend to have larger turbines, particularly offshore, and are expected to reach load factors of up to 48%.

Load factor: A measure of the average output of a power station, relative to its installed capacity. This depends on technical and economic factors. For individual gas, coal or nuclear plants the load factor… Read More

In general, European windfarms generate more electricity in winter, when their load factors are higher. This is shown in the top left panel below (December, January and February, DJF).

Top four panels: Average wind generation load factor between 2006 and 2015 across winter (DJF), spring (MAM), summer (JJA) and autumn (SON). Bottom four panels: Increases (red) and decreases (blue) in projected load factors under 1.5C of warming across the four seasons. Adapted from Hosking et al (2018).

North European windfarm load factors are projected to increase slightly in all seasons under 1.5C warming, shown in red colouring in the lower panels. The largest increases are seen in the summer months (JJA), when wind potential is currently lowest, the researchers say.

The paper says:

“We find that wind energy production during spring and autumn under 1.5C forcing would become as productive as it is currently during the peak winter season. Similarly, summer winds would increase driving up wind generation to resemble levels currently seen in spring and autumn.”

Hosking says this extra energy at a time when wind contributes comparatively less to the UK energy mix could be helpful. He says:

“An increase in renewable energy in the summer could be a very important source to mitigate against increased use in, say, air conditioning as we see warming temperatures during the summer months.”

Low confidence

Today’s study is the first to look at how warming will affect European wind power potential using the HAPPI models. However, several earlier studies have already investigated this question in other ways.

Last year, a study covered by Carbon Brief came to the opposite conclusion to today’s work, finding warming would reduce wind power potential in the UK.

One difference is that this research looked at significantly higher levels of warming than today’s research.

Hosking is not concerned about this contrasting result. He says:

“The changes in wind with changes of global temperature are non-linear; we don’t expect the same patterns of wind change at different levels of global warming. So at this lower level of global warming at 1.5C…our paper showed that we’ll see an increase.”

“The HAPPI dataset is specifically designed for the IPCC special report on 1.5C warming, so we’ve based our analysis on the best available data for a 1.5C warming world…Other climate model datasets which are used for general climate change are not suitable for this kind of analysis.

Still, it is important to emphasise the complexity in pinning down future wind speeds. For example, the North Atlantic westerly winds are highly variable, making it challenging to predict how they might change as the world warms. The IPCC’s Fifth Assessment Report, published in 2007, said:

“Confidence in future changes in windiness in Europe remains relatively low. Several model studies have suggested increased average and/or extreme wind speeds in northern and/or central Europe, but some studies point in the opposite direction.”

With different studies continuing to show very different impacts of warming on wind speed potential, this IPCC conclusion still remains valid today.